Iran’s defense minister met Tuesday in Moscow with Russian President Vladimir Putin about delivery of the advanced S-300 air defense system -- and the purchase of powerful offensive weapons, including Russia's most sophisticated tank and jet fighters.

Russian media and two intelligence officials speaking to Fox News confirm the meeting between Putin and Brigadier General Hossein Dehqan, believed to be the architect of the 1983 terror bombing that killed 220 U.S. Marines and 21 other service members in Beirut, Lebanon.

A United Nations resolution passed on July 20, days after the landmark nuclear agreement between Iran and six world powers, including the United States, forbids Iran from making conventional arms sales for the next five years.

While a defensive “ground-to-air” weapons system such as the S-300 is exempt from U.N. Resolution 2231, the ban explicitly forbids “battle tanks, armored combat vehicles, large-caliber artillery systems, combat aircraft, attack helicopters, [and] warships…” from being purchased by Iran without prior approval from the U.N.

Iran is looking to buy Russia's most capable tank, the T-90, as well as modern Su-30 Flanker fighter jets, Dehqan has said.

The State Department would address any concerns over Iran-Russia transactions by speaking directly with Russia or at the U.N., a department official told Fox News.

Dehqan's arrival in Moscow Monday comes a month after Iran received billions of dollars worth of sanctions relief when the nuclear deal between Iran and world powers went into effect.

Iran freed five American hostages on the same day.

In late December, Iran transferred 25,000 pounds of low-enriched uranium and weeks later capped its plutonium reactor in Arak, fulfilling its obligations under the deal.

This is not the first time Iran has appeared willing to violate U.N. Security Council resolutions. Fox News was first to report that Iran carried out a medium range ballistic missile test in November.

Intelligence officials said the Nov. 21 test launch was held near Chabahar, a port city in southeast Iran’s Sistan and Baluchestan Province near the border with Pakistan. The launch took place from a known missile test site along the Gulf of Oman.

The Ghadr-110 missile tested by Iran has a range of 1,200 miles, and is capable of carrying a nuclear warhead. The missile fired in November is an improved version of the Shahab-3, and is similar to the precision-guided missile tested Oct. 10 by Iran, which elicited strong condemnation from members of the U.N. Security Council.

Last month, the U.S. Treasury sanctioned 11 entities and individuals linked to the October ballistic missile launch, after seven House Democrats, including the chairwoman of the Democratic National Committee, wrote a letter to President Obama urging him to take action.

The Obama administration has not publicly acknowledged the November launch.

In January, Iran detained 10 U.S. Navy sailors and held them for 15 hours on the same day as President Obama’s State of the Union address.

Hours after the sailors were released, Secretary of State John Kerry said his strong relationship with Iran’s foreign minister forged during months of negotiating the nuclear agreement led to a quick resolution to the incident.

“All indications suggest or tell us that our sailors were well taken care of,” Kerry said the day the sailors were released, January 13.

Iran later released pictures showing the U.S. sailors surrendering. A video released on Iranian State TV showed a young Navy lieutenant apologizing. The images and video outraged senior U.S. officials.

Last week, Iran released another video showing one of the U.S. sailors crying in captivity. Days later, Revolution Day parades across Iran celebrating the 1979 Islamic Revolution displayed floats with actors simulating the surrender of the U.S. sailors which drew cheers from the crowds.

In late December, as the USS Harry Truman, an American aircraft carrier, transited the Strait of Hormuz, an Iranian missile boat fired a number of unguided rockets only 1,500 yards away, an act the U.S. Navy called “highly provocative.”

Officials say Iranian-Shiite militias backed by Russian airstrikes have tipped Syria’s civil war in favor of the regime. Since late September, Russia has conducted 90 percent of its airstrikes against opposition fighters, some backed by the U.S., according to defense officials.

Last weekend in Munich, the United States and 16 senior world leaders failed to stop Russia and Iran from continued violence against civilians and opposition groups battling the Assad regime.

A Syrian opposition leader asked leaders attending the 52nd Munich Security Conference to not forget the lessons of World War II and urged them to stand up to Russia and Iran.

“The Allied forces could not have won that war with a policy of appeasing dictatorships and totalitarian regimes, which they must confront with decisiveness,” said Riad Hijab.

Hijab called for the “neutralizing” of Russia, Iran and its militias in Syria, which he called a “real source of terrorism.”

Lucas Tomlinson is the Pentagon and State Department producer for Fox News Channel. You can follow him on Twitter: @LucasFoxNews